Assembly of parts such as cylinder heads, engine blocks, axles and transmissions originally were performed manually with the parts to be assembled being installed by workers with hand tools. Parts, such as caps, spark plug tubes, cup plugs, ball seals, dowel pins, oil restrictors, bearings seals, crush spacers, bushings, and the like, are pressed into openings that may be coated with a lubricant/sealer. Problems with manual assembly operations include inconsistent results, assembly quality defects, and excessive labor costs.
Dedicated assembly lines were developed to increase consistency and reduce labor costs. However, dedicated assembly lines lack flexibility and are limited to assembling one model of a part and cannot be used for other similar parts without substantial changeover downtime. Dedicated assembly lines make it difficult to control of the quality of pressed-in component part operations. If a part is improperly installed, omitted from an assembly, or the wrong component is installed, the part must be taken off-line for repair or scrapped. If a new part assembly line is developed, long lead times are required to build new dedicated tools. Dedicated pressing operation tools require a substantial amount of manufacturing floor space and capital investment.